GPSMAP 4000 Series Owner’s Manual 53
Using Sonar
USinG
Sonar
Advanced Sonar Settings
To adjust advanced sonar settings, press MENU while viewing a sonar screen.
Gain—control the sensitivity of the sonar receiver (Auto or, to adjust manually, Up or Down). To
see more detail, increase the gain. If the screen is cluttered, decrease the gain.
Pause Sonar—select to stop scrolling. Select Create Waypoint to save the location as a waypoint,
and select Resume to continue scrolling in real time. For more information on waypoints, see
page 25.
Frequency—select how the frequencies appear on screen (200kHz, 50kHz, or Dual) when using a
dual-frequency transducer.
Zoom—zoom in to a section of the Full screen. The zoom is off (No Zoom) by default. Three other
options are available:
2x Zoom—twice the magnication. Select Up, Down, or Auto to set the depth range of the
magnied area.
4x Zoom—four times the magnication. Select Up, Down, or Auto to set the depth range of the
magnied area.
Bottom Lock—lock the zoom window to the bottom. Select Up, Down, or Auto to set the depth
range of the magnied area.
Range—adjust the range of the depth scale on the right side of the screen (Auto, or to adjust
manually, Up or Down).
Sonar Setup—open the Sonar Setup screen (page 52).
•
•
•
